The invention relates to a method for the simultaneous dissection in specific position of filiform organic molecular chains, in particular for the sequence-specific dissection of DNA. The dissection of DNA at predetermined positions is a fundamental technique of molecular biology. To date, in routine laboratory works only such enzymes are used (restriction enzymes) which have a specific dissection sequence. The enzyme EcoRI, for example, dissects double-stranded DNA at all positions with the following base sequence:
5′ G A A T T C 3′ 5′ G A A T T C 3′
Such dissections are used in routine work for the manipulation of DNA, for example for the integration of new fragments or for a defined reduction. A complete field of DNA analytics, known as fingerprinting, is based on the variation of length distribution of DNA after the use of such enzymes, the length distribution is documented in the restriction fragment length polymorphism. If there is a mutation in the field of one dissection sequence in singular individuals (that is for example an A instead of a T in the scheme given above), the DNA cannot be dissected at this position, and DNA fragments develop which have other lengths than the ones in individuals without mutation at this position. Therefore, the pattern of the length distribution can be used for identifying the individual man. This fact is made use of for forensic purposes or for paternity affiliations. The extremely high sensitivity of this technique applied for this purposes (the change of an individual base can be detected) is also used for the determination of genetic defects (such as hereditary diseases) which are localized on the dissection sequences. When using all these techniques, however, one is restricted to the naturally existing enzymes and their dissection sequences, other positions cannot be dissected in this manner.
To avoid such restrictions single molecule based techniques have been developed for dissecting DNA at any positions by using a laser beam [Schütze, K., I. Becker, et al. (1997) “Cut out or poke in the key to the world of single genes: laser micromanipulation as a valuable tool on the look-out for the origin of disease” Genetic Analysis 14(1): 1-8)] or by using the atomic force microscope [AFM, Henderson, E. (1992) “Imaging and nanodissection of individual supercoiled plasmids by atomic force microscopy” Nucleic Acids Research 20(3): 445-447]. These two methods have the significant disadvantage that they do not offer selectivity and are characterized by a large dissection width. Laser cutting destroys several hundreds of base pairs and generally an orientation can only be achieved on the basis of typology (start/end) or by means of a fluorescence-marked DNA fragment (FISH: fluorescence in situ hybridization), whereby the optic resolution (>100 . . . 200 nm) limits this method. In addition to this, both methods are single molecule based techniques and do only allow to dissect a single molecule instead of a number of molecules according to the lab standard. Thus, a characterization (for example gel-electrophoresis) or a further processing requires a multiplication in order to be compatible with the standard laboratory methods.
To avoid the limitation caused by the restricted spatial resolution of such physical methods, the proximity focusing technique has been used in material processing. This technique uses a small object (a scanning tip of an atomic focusing microscope having a radius in the lower nanometer range) as a high-intensive secondary light source which is supplied by radiated laser light [Gorbunov, A. A. and W. Pompe (1994) “Thin Film Nanoprocessing by Laser/STM Combination” phys. stat. sol. (a) 145: 333-338]. This secondary radiation becomes effective in the vicinity of the small object (near-field effect), and thus a focusing effect in the size of the object is achieved.